Safety air-valve



n. P. WlTMANf I SAFETY AIR VALVE.

APPLICATION FILED MAR. 14. 1919.

FIG INVENTORD. DANIEL P WITMAN.

l x Patented Oct. 26', 1926.

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Application fil ed March 14,1919. Serial Nb.

ToaZZ whom it may concern.

Be it known that T, DANIEL P. VITMAN, a citizen of the United States, residin at East Somerville, county of Middlesex, ommonwealth of Massachusetts, have invented certain new and useful Improvements in Safety Air-Valves, of which the'iollowing 1 such a machine.

is a specification. 1 I

This invention relates to safety air valves for pneumatic drilling machines and the like, and particularly to a valve handle for The necessityfor an automatic cut-off onsuch machines is well recognized as eliminating accidents heretofore all too common with the ordinary live air handle usually furnished as standard equipment for such machines.

1 'trol and a high-factor of safety.

7 As illustrative of my invention, I have shown as an embodiment a formot' handle which I have found highly satisfactory in practical use and WlliClTlS readily adaptable to all sizes of machines. 3 1

In the drawings: Figure 1 is a central vertical section through the handle.

Fig. 2 a section on the line 22' Fig.

Fig. 3 a section on the line 3-8. Fig. 1 a section on the line 4-4.

In the form shown I have applieda'm'ain sleeve or handle body 1 longitudinallybored from end to end.

Adjacent to one end the handle 1 is red ilced as indicated at 1 and surrounded by a rotatable sleeve 2 held 1n place by the'shoulder of a connection which is tapped into the end of the handle.

The reduced portion 1 is slotted'longitw dinally at 4, to receive a pin 5 which proj ects into a cam slot 6 in the'sleeve 2. The pin 5 which slidingly is tapped into a valve stem 7 fits within the reducedbore 1 The stem 7 is headed on a beveled seat 9'opposite to the intake through the connection 3. The valve stem has a double longitudinal channel as at 10 with an inter-medial guide pin'10 so that the air has practically a direct and straight line admission through the handle'of the of the portion SAFETY AIR-VALVE.

Specification of Letters latent.

sion of the spring resistance of the at 8 and seats PatentedOct. 2 920' 282,598. .1;

5001? The slotis covered at all times'bv the main bodyof the stem 7and the tubular portion 10 which also actsas a guide on the lower end of the stem in its, reduced bore. Within the handle portion 1 the longitudinal bore is enlarged safety valve piece indicated at,11. This piece is slidable in the enlarged bore of the handle 1' below the shouldered entry 12 against whioh it is held by theaction of a for the reception of the spring 13, which spring normally maintains the valve 11in the open position shownin F 1g. 1, against the seating tendency of the incoming air through connection 3; but which is overcome under certain conditions to permit said it particularly disclosed hereinafter. This spring surrounds a hollow stem 14. formed on theconnecting nipple 15. The. nipple '15 has a union connection 16 by which the stem valveto close, as will be more and nipple may be adjustably movedwithin the handle portionl to adjust the COIIIQI'GSi 14. The stem ll-iskeyed at 17' to the handle against any rotative tendency and is in slots 19.

The valve 11 is hollow as indicated at 20 I having lateral ports'21'and'cut away areas 21 and is slidably mounted on the end of the stem 14. IVithinthe valve block '11 is the valve 22 and 7 seat 23. The pressure of the spring 13* hav-i' ing been suitably adjusted by the rotation of the connection 19, themachine may be controlled by the rotation of'thefsleeve 2',

raisingthe valve 8 and admitting airto the machine.

by reason of anystoppage or breakage ofa cuttingtool a back pressure is built up behind valve 11 and with the incoming air d e-t livers a direct thrust on the large .face of. the valve block 11, sul'licient to, overcomefthe spring and close the valve 22 firmly on its seat 28. This immediately shuts oil the. air in time, to avoid the jam of the machine with the consequent dangerto the workmen.

Various modifications may be made in the structureand operation of mysafety handle, all Without departing from'the spirit of my invention if within pendedvclaims. What I therefore claim cure by Letters Patent is r I l. A safety handle of the class described ocked by screws l8 seated on the end of the stem 14 is a If new themachine he suddenly checked the limits of the ap-" projectin Within said bore,

' an enlarged'hand holdand matic shut off comprising a tubular valve seat, a hollow enlarged head slidable on said seat, an interior valve on said head and adapted to find said seat and an adjustable. resilient support abutting said head for sustaining it against pressure.

2, A safety handle of the class described comprising a body member having an axial air passage completely therethrough' from end to end, a positively operable control adjacent one end of said passage and an automatic shut off adjacent the other end f said passage comprising an enlarged valve head closing with the pressure and having. one face formed as a pressure receiving surface constantly exposed directly to said closing pressure in said passage, and its other face formed as a valve, and a seat for said valve and an adjustable resilient support for said head for sustaining it against pressure.

3. .A safety handleof the class described comprising a body member having a central air passage therethrough, a positivelyoperable air control and an automatic shut: off comprising a tubular valve seat, a hollow enlarged head slidable on said seat, an interior valve on said head and adapted to find said seat, and a spring coiled about said tubular seat behind said head forsustaining it against pressure.

4.,A safety handle of the class described comprising a tubular body member having a central bore, a rotatable control sleeve adjacent one end thereof, a valve in said bore and controlled by said sleeve,a member in the opposite end of said bore and having a reduced tubular extension proj ectins with in said bore, a valve seat on the innerend of said extension, a hollow valve head slidably mounted on theend of said extension, an internal valve on said headand a spring'resiliently supporting said valve head against pressure.

of the class described 5. A safety handle comprising a tubular body member having a central bore, EMPOSltlVGlY controlled air supply, a valve in said bore, a member adjustably guided in the opposite end of said bore and having a reduced tubular extension a valve seat on the end of said extension a hollow valvehead slidably mounted on the end of said extension, an internal valve on said head and a spring surrounding said stem and resiliently supporting said valve head against pressure; 7

6. A safety handle of the class described, body member having comprising a tubular a central bore and externally provided with a reduced sleeve bearing, a rotatable control sleeve on said plug member adjustably portion, and providing a bearing, a flanged nipple in the end of said bore and retaining said sleeve, a valve in said-bore and controlled by said sleeve, a

posite end of said here and having a reduced tubular extension projecting within said here, a valve seat on theinner end of said extension, a hollow valve head slidably mounted on the end of said extension, an iiiternal'valve on said head and a spring surrounding said stem and resiliently supporting said valve head against pressure.

7. In a device of the class described, a body member having a bore providing an air passage therethrough, a positively operable control, and an automatic shut off comprising a tubular said bore and having a valve seat at its inner end, and a spring controlled valve slidably mounted on said extension and. adapted to find said seat. I

8. In a device of the class described, a

body member having a bore providing an air passage therethrough, a positively operable formed as a valve adapted to find said seat. 9. In a device of the class described, a body member having a bore providing an air passage therethrough, a positively operable control, and an automatic shut off comprising a into said'bore andhaving a valve seatat its inner end, a valve sleeved about said extension and having an internal valve adapted to find said seat, and a spring abutting said valve for sustaining it against pressure. 10. In combination With a body. portion having a bore providing an airpassage, a hollow head movable in said passage and havingone face formed as a pressure receiving surface constantly exposed to pressure through said bore, and having its opposite face formed as a valve portion.

hollow head movable in said passage and.

as a pressure receivhaving one face formed exposed to pressure ing surfaceconstantly through said bore,

face formed as a valve portion, and having a depending skirt surrounding said valve guiding portion.

In testimony whereof I affix my.sigmature in presence of two Witnesses.

, DANIEL PAULWVITB ATAN.

' WVitnes'ses: 1

VICTORIA LoWDnN, MAiuoN F, Weiss;

guided in the o tubular extension projectingand having its 'opnosite extension projecting into 7 

